This invention relates generally to seating cushions and, more particularly, to waterproof cushions, i.e., cushions whose side layer outer surfaces and, preferably, the filler material thereof, remain dry or easily dryable after exposure to wet weather conditions, and a method for manufacturing the same.
Seating cushions adapted for outdoor use, namely in conjunction with outdoor furniture such as chairs and lounges, are well known. A design criteria of such cushions is that such should be usable, i.e., can be sat upon, substantially soon after the cushions are exposed to wet weather conditions, such as a rainstorm or the like.
Several attempts have been made to design a cushion for outdoor use which satisfies this design criteria. More particularly, one such outdoor cushion is constructed of side layers formed of continuous vinyl sheets attached along their respective peripheral edge regions to define an interior space therebetween in which a filler material, such as shredded polyurethane foam, is located. However due to the air impervious nature of the side layers formed of vinyl sheets, it is necessary to provide openings therethrough in the form of pin holes or the like to prevent the interior space from being air tight and, therefore, to allow the filler material itself to determine the "cushioning" or seating characteristics of the cushion. However, although the vinyl sheet is easily wiped dry after being exposed to wet weather conditions, the provision of openings in the vinyl sheets as discussed above unavoidably allows water to enter into the interior space between them whereupon the filler material becomes wet. Since the vinyl sheets are substantially air impervious (except for the small area thereof provided with openings as described above), a free conduction of air through the interior space is prevented thereby making it difficult if not impossible for the wet filler material to become dry through evaporation in a suitably short time to allow the cushion to be used a reasonable time after improvement of the weather conditions. Thus, if the filler material should become wet, the same tends to remain wet or at least damp for a relatively long period of time thereby not only rendering the cushion impracticle or at least uncomfortable for use but, additionally, presents the possibility that the filler material itself will mildew, the latter tending to occur when the filler material is subjected to continuous cycles of being wet and then dried.
In order to increase the speed with which the filler material would dry after becoming wet, outdoor cushions have been constructed of side layers which, rather than being formed of vinyl sheet material, comprise woven fabric material constructed of vinyl covered nylon or polyester thread. Such woven fabric material generally has a relatively loose or open weave so that relatively large spaces are defined between the filaments of the woven fabric. One type of such plastic coated thread is available under the name Textilene from Twitchell Corp. of Dotham, North Carolina while one type of such fabric is available under the name Textalure from Engineered Yarns, Inc. of Coventry, R.I.
Although the use of such air pervious fabric has resulted in significant improvements in the circulation of air throughout the cushion interior space to thereby facilitate drying of the filler material after the same becomes wet, cushions constructed of such material present other problems. More particularly, when shredded polyurethane foam is utilized as a filler material in such cushions, pieces of the same tend to conglomerate upon becoming wet with the resulting conglomerates tending to fall through the relatively large spaces of the woven fabric which, of course, is quite undesirable. In order to obviate this problem, such filler material has been disposed within a perforated nonwoven roving or bag. However, this provision again resulted in a prolongation of the drying time for the filler material due to the non-woven roving inhibiting air circulation through the cushion interior. Further, water present in the filler material prior to it becoming dry would tend to rewet the outer surface of the side layers upon the cushion being sat upon.
Other attempts to overcome the above discussed problems have focussed on the nature of the filler material itself. Thus, the filler material has been made from polyurethane foam in slab form. Although such provision has overcome the problem of shredded filler material tending to conglomerate and fall through the spaces in the woven fabric side layers, the slab foam filler material still requires a relatively long time to dry after becoming wet thereby increasing the chances of mildew. The latter problem is especially acute when the woven fabric of the side layers comprises a relatively loose or open weave which permits ultraviolet rays to pass through the fabric spaces which accelerates the mildewing action. Other disadvantages inherent in the use per se of foam as a filler material, namely, inability to wash the same due to consequent deterioration thereof, of course remain.
It is understood that the problems discussed above are present in various degrees depending upon the particular geographical locale in which the cushion is used. Thus, the filler material in cushions used in, for example, the Southern part of the United States, e.g., Florida, tend to dry faster than in other locations due to the particular weather conditions which prevail. However, the problems still exist to some extent even in such areas and, further, are equally serious in cases where the cushions are of the type that have buttons or like elements fastened to the slab foam material through the side layers in order to fix the filler material in place since air circulation is again obstructed thereby prolonging drying of the filler material.
Still other materials are utilized as a filler material which are chosen so as to promote increased drying rates. Thus, polyester material has found increasing use as a filler for outdoor cushions. Although such material does indeed tend to dry faster than polyurethane foam material, polyester is between 2 and 21/2 times as expensive as equivalent amounts of polyurethane and the wetness problem although not as severe as it has been in the case of polyurethane foam, still persists. Further, the seating characteristics of Dacron material are generally considered as not being as good as those of polyurethane foam.
From the above, it is seen that conventional outdoor cushions which are presently available are not entirely satisfactory for the reasons that firstly, the filler material tends to become wet when exposed to wet weather conditions thereby rendering the cushion unusable and possibly damaging the same and, secondly, when wet, an undesirably long period of time is required for the filler material to dry thereby rendering the cushion unusable for that time and possibly subjecting the cushion filler material to a mildewing action. Attempts to overcome these problems have not been entirely successful and have often resulted in cushions which are unduly expensive in manufacture.